(CNN) -- For Sen. John Kerry, the 2004 Democratic presidential campaign ran much like the relentless Boston Marathon course in his native Massachusetts, full of ups and downs.

The four-term senator finished his race on top, propelled by a decisive burst from the pack during the first binding delegate elections.

But the win wasn't easy nor altogether expected, after Kerry slipped from his early top-tier standing and observers say his campaign fell into disarray.

The Democratic race began, in earnest, when odds-on favorite Al Gore -- vice president under Bill Clinton and the party's 2000 presidential nominee -- announced December 15, 2002, that he wouldn't challenge President Bush in 2004. (Full story)

Following Gore's announcement, his 2000 running mate, Sen. Joe Lieberman, led in most of the polls with around 20 percent support, a point or two above his closest rivals. CNN/USA Today/Gallup polls at the time showed Kerry, aided by his military and political experience, close behind his colleague from Connecticut.

Yet the entire Democratic field's prospects looked bleak early in 2003, with Bush's job approval ratings hovering above 80 percent, according to the same surveys.

Still, the Democrats soldiered on, racking up funds and endorsements. By February 27, 2003, when Sen. Bob Graham of Florida threw his hat into the ring, nine major candidates had formed presidential campaign committees.

A few weeks later, the contentious diplomatic battle over Iraq climaxed with the March 19, 2003, U.S.-led "decapitation strike." Within weeks, coalition troops had stormed through Iraq, ousted Iraqi leader Saddam Hussein, and detained and killed much of his regime.

The race begins

Former Vermont Gov. Howard Dean entered the 2004 as the Democratic front-runner and was endorsed by 2000 candidate Al Gore. But his campaign faltered in Iowa and New Hampshire, and never recovered.

Bush praised the military effort on May 1, declaring an end to major combat operations in Iraq under a banner on the aircraft carrier USS Abraham Lincoln that read "Mission Accomplished."

In the spring coalition forces, Iraqi civilians and even UN personnel came under attack in Iraq, while the U.S. economy was in recovery but was still struggling to create jobs. The Democrats saw a boost in their poll numbers.

The contender leading the grass-roots charge on these issues had been largely an afterthought when he became the first official candidate in summer 2002. But by Labor Day 2003, he grabbed the front-runner title.

Howard Dean, a former governor of the small, largely rural state of Vermont, distinguished himself from the pack by lambasting Bush's policies in Iraq and elsewhere, striking a chord with many dissatisfied Democrats.

Dean found a key voice, and revenue source, online. While supporters spread the word in chat rooms and "meet-ups," his campaign got $7 million between April and June 2003, half of it coming via his Web site during the last nine days of June. (Full story)

His poll numbers picked up as well. CNN/USA Today/Gallup polls indicated a jump from 5 percent of registered Democratic voters in early June to 15 percent in early August, tying Dean with Rep. Dick Gephardt of Missouri and putting him just three points behind Lieberman.

A supporter of the war in Iraq and moderate Democrat, Lieberman lashed out at Dean and other left-wing Democrats, warning they'd move the party into the "political wilderness" by embracing "failed solutions of the past."

What appeared to be a Dean juggernaut rolled on regardless, as the candidate appeared on the cover of both TIME and Newsweek magazines in late August.

And then there were 10

Wesley Clark, a former NATO supreme commander and four-star general, seized Dean's momentum on September 17, when he entered the Democratic race. The Arkansas native, who had never sought elected office, instantly rocketed to the top of most polls. (Full story)

The race tightened through the fall, with Clark and Dean heading the field. Kerry, meanwhile, saw his support slip and campaign stumble. He fired his campaign manager November 10, and in December personally loaned his struggling campaign some $7 million -- more than $6 million financed by mortgaging his Boston home. (Full story)

In December, Dean again broke from the pack. After months shunning the Washington, D.C., establishment and touting himself as an "outsider," Dean picked up Gore's backing. Dean also amassed support from a growing group of "superdelegates" -- unpledged elected officials and Democratic National Committee members eager to back the man who suddenly looked like a runaway front-runner. (Full story)

The beginning of the end

North Carolina Sen. John Edwards was Kerry's main competition but was unable to derail Kerry's campaign on Super Tuesday.

But the first binding elections were still a month away. Dean and Gephardt waged a bitter battle in Iowa on January 19, while Sens. John Edwards and Kerry remained positive while reallocating much of their resources in an all-for-nothing bid in the Hawkeye State.

Dean picked up two key endorsements days ahead of the primary, from Sen. Tom Harkin of Iowa and former candidate Carol Moseley Braun. But under the glare of the media spotlight, questions about Dean's temperament, campaign trail missteps and 2000 criticism of the importance of the Iowa caucuses took their toll.

Polls released days ahead of the January 19 contest showed the race tightening, with a January 15 Reuters survey indicating a three-way tie between Kerry, Dean and Gephardt and a later Des Moines Register poll putting Kerry narrowly ahead of Edwards.

On caucus night, Iowa voters gave Kerry a huge victory, with Edwards finishing a strong second. Dean placed a disappointing third with 18 percent of the vote and Gephardt came in fourth, terminating his second presidential bid the following day. (Iowa results)

The outcome gave the Massachusetts senator the momentum heading into the January 27 New Hampshire primary. After avoiding Iowa, Clark and Lieberman sought to make their first stand there. Dean gunned for his first win in a state where, a month earlier, he'd held a 45 percent to 13 percent lead over Kerry, according to an American Research Group poll.

Kerry cemented his newfound front-runner status with a Granite State victory. Dean placed second followed by Clark, Edwards and Lieberman -- all within a few percentage points of one another. (New Hampshire results)

Edwards broke through February 3 by winning South Carolina's primary, while Clark eked out a win in Oklahoma. But, again, Kerry was that day's big winner, capturing five of seven states. After poor showings in every contest, Lieberman dropped out. (February 3 results)

By mid-February, as Kerry compiled wins and convention delegates in Maine, Tennessee and Virginia, his fellow Democrats fought to outlast their rivals for the right to challenge Kerry, one-on-one.

Clark ended his bid first, dropping out February 11 and quickly endorsing Kerry. Howard Dean followed suit a week later, after losing what he previously described as a "must-win" primary in Wisconsin.

That left Edwards, the senator from North Carolina known for his Southern charm and positive campaign message, as Kerry's lone real competitor.

But the Bay State legislator's steamroller could not be contained. Edwards exited the race Wednesday, March 3 after Kerry won all but one -- Vermont, which went to Dean - of 10 contests the day before on "Super Tuesday." His victories that night also earned him a congratulatory call from his next opponent -- President Bush. (Super Tuesday results)

By the second week of March, a CNN survey showed Kerry had earned enough delegates and superdelegates to wrap up his party's nomination.